As heavy industry embraces renewable energy, many operators are turning to hybrid power systems—combinations of solar, wind, diesel, and battery storage—to reduce costs and emissions. But these changes bring new challenges for electrical protection, coordination, and arc-flash safety.
At Venn Power, we’ve seen that the most successful industrial energy transitions start not with equipment selection, but with protection design.
Why Protection Design Matters in Hybrid Networks
Traditional industrial networks were built around large synchronous machines. Protection schemes were simple—fault currents were predictable, fault directions were clear, and settings were stable.
Hybrid systems change that. Inverter-based resources such as solar and BESS introduce controlled or limited fault current. They can alter system strength, short-circuit levels, and even fault direction.
Without design updates, this can lead to:
- Protection mal-operation or non-operation
- Hidden reliability risks during mode changes
- Increased arc-flash energy in unexpected parts of the system
Rethinking Fault Current and Coordination
A common misconception is that lower fault current means lower risk. In reality, it often means reduced visibility for protection devices.
Inverter-dominated systems may not generate enough current to trip legacy relays quickly. Coordination studies must therefore consider multiple operating modes—diesel-only, solar-dominant, or fully islanded—to ensure coverage in every condition.
Modern digital protection relays, adaptive settings, and scenario-based simulations help achieve this balance. At Venn Power, we model fault scenarios for each generation mode to define realistic set points, discrimination margins, and clearing times.
Arc-Flash Energy: A Hidden Consequence of System Change
When system impedance or fault contribution changes, so does arc-flash energy. Adding renewables or BESS can alter upstream fault levels and therefore arc duration.
We’ve found that even minor network changes can shift incident energy levels enough to affect PPE requirements or maintenance boundaries.
That’s why every hybrid integration project should include:
- Updated short-circuit and arc-flash calculations
- Review of protective device coordination
- Validation of relay clearing times for new operating states
Addressing these early ensures compliance with Australian standards, while maintaining site safety.
Design Integration: More Than Compliance
Protection and arc-flash analysis shouldn’t be treated as an afterthought or a compliance checkbox. They are key to reliability, safety, and operational flexibility.
By reviewing system strength and refining relay coordination, false trips and downtime can be eliminated. Successful hybrid power design requires protection as a design discipline, not an after-the-fact correction.
Best Practice for Industrial Hybrid Systems
- Start with System Studies – Perform load-flow, fault, and stability studies early.
- Design for Multiple Modes – Account for varying generation mixes and transitions.
- Update Protection Coordination – Re-assess relay logic, grading margins, and fuse selectivity.
- Review Arc-Flash Hazards – Recalculate incident energy for each configuration.
- Engage Early – Involve electrical engineers experienced in hybrid systems and inverter-based technologies.
Future-Ready Protection Design
As industry moves toward carbon-neutral operations, hybrid systems will become standard. The key to success lies in engineering protection systems that evolve with technology—ensuring safety, reliability, and compliance from day one.
At Venn Power, we combine research, engineering, and design to help industrial clients integrate renewables without compromising protection performance or arc-flash safety.
Need support with hybrid system protection or arc-flash assessment?
Contact our team at Venn Power to discuss how we can help ensure your system is safe, compliant, and future-ready.
About the Author
Clement Venter is the Director of Venn Power and a Chartered Professional Engineer with over 20 years in the energy sector. He shares insights from his unique approach combining research, engineering, and design to drive smarter, more innovative energy solutions.